...and welcome to the Zoo!

Part of the reason why a YSO section is needed is to try and make some sense of how the different types of variable star fit into some sort of scheme. Should we view the various types as distinct, or should we look at behaviour instead? Pursuing the zoo theme for a while, how do the various types of YSO fit into the interstellar ecosystem?

Something you need to consider carefully, and a question that comes up often with new observers is "How often should I observe my program stars?" The answers depend largely on the type of stars you are observing. The following table is a general guideline. As you learn more about the different types of variables, and the personalities of some of the specific stars you choose to observe, you may decide to observe them more or less often than suggested here.